Are there tickets/documents explain how data be replicated on Virtual Nodes? If there are multiple tokens on one physical host, may a chance two or more tokens chosen by replication strategy located on same host? If move/remove/add a token
manually, does Cassandra Engine validate the case?
Thanks.
On Jan 30, 2013, at 12:46 PM, Zhong Li wrote:
>> You add a physical node and that in turn adds num_token tokens to the ring.
>
> No, I am talking about Virtual Nodes with order preserving partitioner. For an existing host with multiple tokens setting list on cassandra.inital_token. After initial bootstrapping, the host will not aware changes of cassandra.inital_token. If I want add a new token( virtual node), I have to rebuild the host with new token list.
>
> My question is if there is way to add a virtual nodes without rebuild it?
>
> Thanks,
>
> On Jan 30, 2013, at 10:21 AM, Manu Zhang wrote:
>
>> On Wed 30 Jan 2013 02:29:27 AM CST, Zhong Li wrote:
>>> One more question, can I add a virtual node manually without reboot
>>> and rebuild a host data?
>>>
>>> I checked nodetool command, there is no option to add a node.
>>>
>>> Thanks.
>>>
>>> Zhong
>>>
>>>
>>> On Jan 29, 2013, at 11:09 AM, Zhong Li wrote:
>>>
>>>> I was misunderstood this
>>>> http://www.datastax.com/dev/blog/virtual-nodes-in-cassandra-1-2 ,
>>>> especially
>>>> "If you want to get started with vnodes on a fresh cluster, however,
>>>> that is fairly straightforward. Just donít set the
>>>> |initial_token| parameter in your|conf/cassandra.yaml| and instead
>>>> enable the |num_tokens| parameter. A good default value for this is 256"
>>>>
>>>> Also I couldn't find document about set multiple tokens
>>>> for cassandra.inital_token
>>>>
>>>> Anyway, I just tested, it does work to set comma separated list of
>>>> tokens.
>>>>
>>>> Thanks,
>>>>
>>>> Zhong
>>>>
>>>>
>>>> On Jan 29, 2013, at 3:06 AM, aaron morton wrote:
>>>>
>>>>>> After I searched some document on Datastax website and some old
>>>>>> ticket, seems that it works for random partitioner only, and leaves
>>>>>> order preserved partitioner out of the luck.
>>>>> Links ?
>>>>>
>>>>>> or allow add Virtual Nodes manually?
>>>>> If not looked into it but there is a cassandra.inital_token startup
>>>>> param that takes a comma separated list of tokens for the node.
>>>>>
>>>>> There also appears to be support for the ordered partitions to
>>>>> generate random tokens.
>>>>>
>>>>> But you would still have the problem of having to balance your row
>>>>> keys around the token space.
>>>>>
>>>>> Cheers
>>>>> -----------------
>>>>> Aaron Morton
>>>>> Freelance Cassandra Developer
>>>>> New Zealand
>>>>>
>>>>> @aaronmorton
>>>>> http://www.thelastpickle.com
>>>>>
>>>>> On 29/01/2013, at 10:31 AM, Zhong Li >>>> > wrote:
>>>>>
>>>>>> Hi All,
>>>>>>
>>>>>> Virtual Nodes is great feature. After I searched some document on
>>>>>> Datastax website and some old ticket, seems that it works for
>>>>>> random partitioner only, and leaves order preserved partitioner out
>>>>>> of the luck. I may misunderstand, please correct me. if it doesn't
>>>>>> love order preserved partitioner, would be possible to add support
>>>>>> multiple initial_token(s) for order preserved partitioner or
>>>>>> allow add Virtual Nodes manually?
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Zhong
>>>>>
>>>>
>>>
>>
>> You add a physical node and that in turn adds num_token tokens to the ring.
>